Stuffer box crimping involves continuously feeding yarn or continuous filament tow through the nip of a pair of coacting feedrolls into a crimping chamber, which may or may not be heated and which has some type of arrangement for adjusting the back pressure upon the yarn or tow in the crimping chamber, such as a clapper gate arrangement.
Continuous filament tow, for example, is fed through the nip of the coacting feedrolls into the crimping chamber against the tow that is being held in the crimping chamber by the clapper gate arrangement. The incoming tow thus piles up against the chamber tow with the result that individual filaments become folded, convoluted and compressed. This continues until at some point in time, dependent upon feed rate, chamber geometry and the extent of back pressure, crimped tow is forced out the discharge opening of the crimping chamber by other incoming tow.
The continuous filament tow may be made from any of the man-made fibers, such as from cellulose esters, polyesters, polyamides and the like. Some tows have substances in them such as a pigment like titanium dioxide (TiO.sub.2) which causes the tow to have an abrasive wearing effect on the crimping chamber, especially with side structures which abut the endfaces of the nip or feedrolls for the purpose of confining the tow to the nip of the rolls as the tow passes into the crimping chamber. These side structures can become so worn as to cause poorly formed edges on the tow passing through the crimping chamber and even tearing and breaking of the filaments that come into contact with the worn side structures.
These side structures may take a variety of different forms. U.S. Pat. No. 3,249,979 discloses a stuffer box crimper that has replaceable disc inserts which bear against the outer faces of the rotating rolls of the stuffer box. U.S. Pat. No. 3,120,692 discloses plates 3a,3b that serve as such side structures and are of a different configuration than the aforementioned discs. The design of some discs or plates is such that the disc or plate may be removed and turned around so as to present a fresh surface to the endfaces of the coacting feedrolls when the initial surface of the disc or plate starts to show wear.
In many cases, the design or placement of the stuffer box crimper is such that it is necessary to shut the stuffer box crimper down before the operator can safely remove the discs or plates and reinsert and/or replace with new ones without causing injury to the operator and/or damage to the stuffer box crimper and to the disc or plate the operator is attempting to reinsert.
If a stuffer box crimper has to be shut down to change or replace the side plates or discs, then normally this may mean one of several things: (1) if the tow is coming directly from spinning cabinets, then the spinning cabinets upstream of the stuffer box crimper must either be stopped or the tow must be allowed to go to waste; or (2) if the tow is coming from containers or tubs then it is only necessary to stop the stuffer box crimper and any necessary equipment upstream between the stuffer box crimper and the containers or tubs.
An object of the invention, therefore, is to provide an arrangement by which a side structure called a "cheekplate" may be safely removed, reinserted and adjusted relative to the endfaces of the coacting feedrolls of a stuffer box crimper while the feedrolls are still rotating; i.e., without having to stop the operation of the stuffer box crimper or any of the other operating equipment upstream of the stuffer box crimper.